BTU Calculator (USA)

Instant AC sizing estimate in BTU/h, tons, and watts. Adjust for insulation, sun exposure, people, and electronics. Download a simple PNG report.

Instant results
📱 Mobile-friendly
🧾 1-click PNG
Estimated required load
12,000
BTU per hour
Cooling tons1.0 Ton
Approx. watts3,516 W
Informational estimate only. Real HVAC sizing depends on ceiling height, windows, infiltration, climate zone, and construction details.

How BTU sizing works

BTU/h (British Thermal Units per hour) measures how much heat an air conditioner can remove. A common reference is that 1 ton of cooling = 12,000 BTU/h. Proper sizing improves comfort and energy efficiency.

Undersizing may run constantly. Oversizing can short-cycle and remove less humidity. Use this tool as a starting point and verify final sizing with a licensed professional.

Frequently asked questions

How do I estimate BTU from square footage?

Start with room area and adjust for insulation, sun exposure, people, and electronics. This calculator automates those steps.

What does “tons” mean in HVAC?

Cooling tons are another way to express capacity: 1 ton = 12,000 BTU/h.

Should I round to a standard AC size?

Yes—real units come in standard increments. We round to common sizing steps to keep results practical.

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